From 3a7c384ffd57ef5fbd95f48edaa2ca4eb3d9f2ee Mon Sep 17 00:00:00 2001 From: Eric Dumazet <edumazet@google.com> Date: Thu, 9 Aug 2012 13:56:06 +0000 Subject: [PATCH] ipv4: tcp: unicast_sock should not land outside of TCP stack commit be9f4a44e7d41cee (ipv4: tcp: remove per net tcp_sock) added a selinux regression, reported and bisected by John Stultz selinux_ip_postroute_compat() expect to find a valid sk->sk_security pointer, but this field is NULL for unicast_sock It turns out that unicast_sock are really temporary stuff to be able to reuse part of IP stack (ip_append_data()/ip_push_pending_frames()) Fact is that frames sent by ip_send_unicast_reply() should be orphaned to not fool LSM. Note IPv6 never had this problem, as tcp_v6_send_response() doesnt use a fake socket at all. I'll probably implement tcp_v4_send_response() to remove these unicast_sock in linux-3.7 Reported-by: John Stultz <johnstul@us.ibm.com> Bisected-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Eric Paris <eparis@parisplace.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Signed-off-by: David S. Miller <davem@davemloft.net> --- net/ipv4/ip_output.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 76dde25fb9a04..ec410e08b4b9e 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -1536,6 +1536,7 @@ void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, __be32 daddr, arg->csumoffset) = csum_fold(csum_add(nskb->csum, arg->csum)); nskb->ip_summed = CHECKSUM_NONE; + skb_orphan(nskb); skb_set_queue_mapping(nskb, skb_get_queue_mapping(skb)); ip_push_pending_frames(sk, &fl4); } -- GitLab